CircleCI: Upgrade grabpl (#26196)

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

.circleci/config.yml

@@ -56,7 +56,7 @@ commands:
       - run:
           name: "Install Grafana build pipeline tool"
           command: |
-            VERSION=0.4.20
+            VERSION=0.4.21
             curl -fLO https://grafana-downloads.storage.googleapis.com/grafana-build-pipeline/v${VERSION}/grabpl
             chmod +x grabpl
             mv grabpl /tmp